Vesper Research  
   Sells the a non-electric room humidifier as well as a water purifying pitcher. Offers testimonials and policies.
   http://www.vesperresearch.com/

SureSource  
   Presents the Bemis product line, including accessories and parts.
   http://www.bemis-store.com/

All4Elements  
   Sells a range of Ultrasonic Room Humidifiers. Provides a buying guide and addresses the reasons to humidify.
   http://www.humidifiersdirect.com/

Spring Air Products  
   Markets a on-furnace humidifier. Provides installation instructions as well as a FAQ page.
   http://www.dspringair.com/

Miller Electric  
   Produces a whole house furnace humidifier that attaches to a forced air heating system. Includes photos and installation instructions.
   http://www.millermister.com/